The Blue Spirit
by BoysInBleachAreBetter
Summary: Zuko and Katara pursue a secret relationship over the course of season 2/3, beginning when the pirates are introduced. Woven into the original story, this includes all the moments you wished had actually been moments. MA.
1. Chapter 1

"There _is_ a way you could be free of him."

The crystals embedded in the cave walls were providing enough light for the two of them to see each others faces clearly. In a twisted way, the crystal catacombs of Ba Sing Se were beautiful. Zuko and Katara were all alone in the vast cavern, sitting together by a small underground lake.

She had begun to play with the water absent-mindedly—small whirlpools danced and collided before them as she considered Zuko's plan.

"You know it will come to it soon," he murmured, letting his hand trace circles over the soft skin of her leg. "When Azula and I take the city I will have the choice to go home. I want you to come with me."

Katara shook her head, trying not to meet his golden eyes. She could picture the slight eagerness there that would make her willpower crumble. "Aang would never believe I went with you willingly," she sighed heavily, "He would pursue us all the way back to the fire nation—he would lose the _war_ if it meant getting me back."

Her fists were closed tightly, the skin across her knuckles pulled taught with stress. The whirlpools had become larger and more chaotic. Zuko placed his hands over hers and the water stilled. "That is why we have no other option." His voice was confident.

"You're asking me die."

"To _pretend_," he urged, "only _then_ will the Avatar will give up."

"It would break my brother's heart," Katara whispered.

Zuko grabbed her chin gently and turned it towards him, placing a slow kiss on her forehead. "If we separate again, it would break mine. I need you Katara. Come home with me."

**Note: This story runs parallel to season 2 and 3 of the series. It stays true to most of the original plot, though I've woven Katara and Zuko's secret relationship into the gaps. Enjoy!**

In the hours it took for Iroh and "Team Avatar" to find the duo, Katara and Zuko resolved to treat them as though it would be their last chance to be together, for after all, their plan was risky and likely to fail.

In the light of the crystal tomb Zuko steadily undressed her, pulling at the fabric of her robe with purpose. His kisses were literally fire on her skin, as if he were trying to leave his mark there. No matter how the next few hours transpired, they would not forget these moments.


	2. Chapter 2

"When you return home, father will welcome you as a war hero."

Zuko's face had become twisted with indecision, though Katara knew it was a lie—he was a good actor. He hesitated for what seemed to be an age, caught between his polarizing loyalties. General Iroh's eyes were pleading. Zuko struck him down regardless, knowing what was at stake. He had picked a side. He had made his choice.

Azula's eyes gleamed with satisfaction. In the battled that ensued, Zuko and Katara sparred with energy—they had to make it genuine. Aang was constantly stealing glances in between blows with Azula, clearly concerned for Katara's safety. He needn't have been of course—Zuko's powerful blows glanced but never fully struck the clever water-bender, but it was time for the finale. It was crucial that Aang see Katara fall.

Katara and Zuko began to spar with more intensity. With a quick kick from Zuko, Katara was stumbling backwards. Taking a deep breath in, he delivered his final strike. A raging inferno of a fireball shot towards Katara impossibly fast. He saw her eyes widen in very real fear, though at the last moment he let the intensity come right off so that when it connected with her it was at less than half it's original heat. Regardless, Katara let out a horrible scream as she was thrown backwards into the cave wall.

Seeing her crumpled in on herself was horrible for Zuko, made only more horrifying by the burns he could see blistering at her skin. He turned to Azula and Aang who had both seen it happen. Whilst Aang froze in shock, Azula made the most of the distraction and struck him with her most powerful lightning strike yet.

Zuko had fulfilled his duty to the fire nation. He would now return home a hero. And unknown to the rest of the ship's crew, he would be bringing someone with him.

As he lay awake in his private cabin aboard a ship far more luxurious than the one he and his Uncle had called home, he felt only guilt. Katara lay beside him, her skin now fully healed. Though she had assured him that she was okay, he couldn't shake the memory of how scared she had been as he attacked her, and how scared _he_ had been seeing her unmoving in front of him.

Zuko placed a kiss on her shoulder. "I'll never hurt you like that again," he murmured, thinking she was asleep.

"I believe you," she whispered.


	3. Chapter 3

_Going back to the beginning..._

"Shoot. Come _on_ water, work with me here."

The floating beads refused to fuse. They were like repelling magnets—they could be forced beside each other, but they would no properly combine. _I suppose I could fire them individually._ Katara shuddered at the thought of what that would do to a human body.

"Ok Katara, shift your weight through the stances." She began to make her movements more fluid like the river beside her. A distant sound broke her focus, and the water struggled and failed. Rushing to the edge of the river, she spotted them upstream. _Oh no. They've found us_. Black smoke began to fill the already darkening sky. The metallic stench of iron and coal and death and destruction had reached her almost instantly. She bit her lip anxiously and turned to warn the others.

No sooner had she begun to run, the sound of heavy footsteps manifested behind her.

Within moments they were on her. Rough hands wrapped themselves around her torso and lifted her off the ground, before throwing her into the nearest tree trunk. Winded and dazed there was no chance for her to recover before she was grabbed once more—though this time weathered hands held her in place.

"No! Let go of me!"

Using her only free hand she fashioned the nearest puddle into a whip and fired it at her assailant, but it evaporated before it even got close. The figure responsible was walking towards them. As he emerged from the shadows, Katara's expression hardened.

Scarred face. Scarred smile. We've met before—Prince Zuko.

"I'll save you from the pirates," he smiled.

"Tell me where he is and I won't hurt you or your brother."

Zuko was standing before a line of expressionless skulls—red horns reminiscent of the demons Katara feared as a child. The clearing was about half an hour's walk from campsite where the others were setting up camp.

"Go jump in the river." She wasn't giving them up.

"Try to understand—" Zuko reasoned, circling her slowly, "I need to capture him to restore something I've lost…my honor." He stopped pacing and positioned himself behind her, "Perhaps in exchange I can… _restore_ _something of yours._"

His lips had only brushed her ear slightly, but the heat was enough to redden her cheeks and send her fire through her body. So when she felt the cool of her pendant at her chest, it was like ice against her skin.

"My mothers necklace," she breathed before turning on him, "how did you get that?"

"I didn't steal it if that's what you're wondering." Prince Zuko looked mildly angry at the accusation in her voice, "tell me where the Avatar is."

"No."

He pulled the necklace away from her neck in disgust.

"Prince Zuko, we can't find them and we're losing the light."

The soldier was dripping wet and shivering. The weather had worsened significantly in the last few hours of their search. Without the girls cooperation this was becoming impossible—the forest was too large to search with only a handful of men.

"Return to the ship."

"And what of the water tribe peasant?"

Zuko considered his options for a moment, glancing at the tied up girl. She was watching him too—her eyes hungry with anger, "take her back to the ship. We can bargain with her tomorrow."

Hearing this, her expression faltered slightly. There was a barely noticeable defeat in her shoulders as they took her away.


	4. Chapter 4

**Warning: chapter contains explicit content. **

Neither of them spoke for some time. Katara's hands were temporarily unbound to allow her to eat, but her food was untouched (as was Zuko's). He did not eat much these past few months. Stress and fatigue had sapped his appetite completely.

General Iroh however, having finished his meal, now sipped at his tea happily, letting his gaze wander between the pretty water tribe girl and his surly nephew.

"So, your name is Katara isn't it?"

Katara looked up from her untouched rice, caught off-guard by the old mans friendly tone. After considering his question for a few moments she nodded. Iroh accepted this answer and continued.

"Well Katara, I'm sorry that we're doing this to you."

"Uncle!" Zuko snapped, "don't apologize. She's harboring a fugitive of the fire nation."

Iroh shook his head, "no, she's protecting a friend. You'd do the same," then almost to himself he murmured, "_If you had any._"

"What?"

"Nothing."

"I think it's time for your patrol shift Uncle."

"Ok, ok," Iroh stood and stretched his back before heading towards the door to leave. At the threshold he paused, murmuring so low that only his nephew could hear, "Zuko, hostage or not, you should treat Katara kindly. Do not forget the compassion they showed you in the North Pole."

Zuko had not forgotten. Looking at the girl across the table he met her eyes. They were not burning with the same fiery hatred that he had become accustomed to—instead they appeared weary. He was not surprised. This girl had been running for a long time.

He turned to his uncle and nodded.

Katara was shivering like mad. She had been tied to that tree for two hours before they called the search off, and in that time the cold had seeped through to her bones.

The pirates boat was no warmer. Even in the cabin the furniture was cold to touch, and the fire unlit. Had her hands not been bound she would have tried to start it. _Water-bending cannot keep you warm_, she thought bitterly.

Looking around the cabin she couldn't help but ache for the comfort the mattress in the corner. It had been so long since she had slept somewhere comfortable and away from the elements. Ironically, here and now as a prisoner of the fire nation, she felt safer.

After all, who was she going to run from now? What else was there to fear? They'd already caught her.

_He_ had already caught her.

The door opened and closed. They were standing at opposite ends of the small space—Katara in the far corner by the window, Zuko by the door. When he spoke, his voice was sharp. "Get some sleep."

"Get out."

He shook his head, "what, so you can escape in the night? No. I cannot let you get away."

She shook her head. "You don't understand."

"What don't I understand?" His posture was still rigid, his arms crossed defensively across his chest.

"I know what waits for me out there," her voice was bitter, "I have already sacrificed my life. I am already dead." Her shivering was beginning to become more obvious. Zuko considered the unlit fire for a moment. Deciding that it would be hard to bargain with a dead hostage, he set the kindling in the fireplace alight. The room's temperature instantly soared.

"Thank you," Katara murmured, pulling her knees up to her chest.

Zuko gazed into the fire he had just created. "I'm not going to kill you."

"That's not what I mean." When he shifted his eyes to hers she continued sadly, "Aang is very powerful. But he is also very childlike. He feels protective over me, and I fear he will never let me travel my own path. In his mind, we are destined to be together. He will never let me stray from his plan for us."

Zuko was still watching her. She noticed his gaze and looked away.

Finally he spoke. "Go to sleep Katara."

"Will you leave now? I'm not going anywhere."

"Nor am I."

The temperature of the room was too hot. Katara had only slept an hour before the heat became too much. Zuko was asleep on a bed of furs by the corner. He had removed his armor, now dressed only in the bottom half of his robe. She could see the gleam of the fire against the muscles in his back.

After becoming sure that he was asleep, Katara stripped down to her sarashi. The thin fabric separating her skin from the heat was not enough to cool her down. Spying the jug of water beside the door she rose to her feet and silently made for it, fully intending to douse the fire with it. With her hands bound, she could not bend it.

She had not reached the jug before Zuko began to stir. Apparently her footsteps had not been as silent as she had thought. Little did she know that Zuko did not sleep much these days. Much like his appetite, his desire for sleep now waned when compared with his hunger to find the Avatar. He rose to a sitting position and noticed her watching him. "What are you playing at?" he accused, rising to his feet. In one swift motion he had forced her against the door, his forearm pinning her shoulders to the wood.

"Let me go. I was thirsty."

Zuko saw the jug of water she had been aiming for and loosened his hold. Her hands were still bound. She was no threat. For the first time he fully noticed that she had removed her tunic. Without her usual layers of fur he now fully understood her curves.

In a shocking instant he had become hungry with desire, but he suppressed it desperately. With a flick of his hand, the fireplace dimmed to embers. Reaching back to his armor he found his knife and used it to cut her ties. "Have a drink then go back to bed."

Katara followed his instruction, though instead of lying down she turned to him. "Zuko." Her voice was different.

"What?"

"It may sound weird, but this is the most freedom I've felt since leaving my tribe."

He frowned slightly, "you are currently my prisoner. Freedom isn't the right word for your current situation."

Katara looked towards the window. Rain lashed the glass violently. Her attention turned to him once more. "I am alone now to make my own choices. Aang isn't here. I don't have to justify my actions to anyone other than myself." Zuko wasn't really following, which Katara noticed. So her next sentence was fairly blatant. "Zuko, I haven't had contact with anyone for a long time. I want you to change that."

Zuko's body was beginning to gravitate towards her without him noticing. His hands were tugging at his robe, trying to ease the throbbing that was beginning to sweep through him. He noticed what was happening and stopped moving. He became akin to ice.

Katara however was becoming fire. Her fingers gently began to tug at the section of her sarashi that wrapped her chest.

"Stop." Zuko whispered half-heartedly. "Katara, please."

But she had already tugged the fabric loose. The material unwound naturally with gravity and pooled at her feet. She held out her hand in invitation. Her eyes were like melting icebergs—chaotic and steady simultaneously. "Zuko, give me this one night of freedom."

He was no longer exercising restraint. The pull towards her body was too strong. Within moments he had her on her back, but he did not kiss her. Pinning her hips with his, Katara could feel him pressing into her. He squeezed her body against his tightly, rocking his hips every so slightly. Zuko didn't mean to be doing any of this—after all this was _his prisoner. _But she had initiated it? This was all too much for him to consider, though his hands had a mind of their own as they traced hot patterns against the skin of her waist. Like the slow flame of a candle they began to skirt across her collarbones, her neck, her jaw, the edges of her smile. All the while his hips rocking against hers in a deliberate, steady rhythm.

A short, ragged breath escaped her lips. Her restraint was not as strong as his. She lifted her head and their lips met. Simultaneously she let her hips rise to his movements, forcing their bodies together until no negative space could possibly exist.

As they kissed Zuko's hands slipped beneath her remaining clothes, brushing the inside of her thigh. They skimmed dangerously close but diverted at the last moment. He tugged at the material before pulling it free of her body. For a moment he rocked back onto his heels, admiring Katara's curves and soft skin.

"This is familiar," he sneered, "I've knocked you onto your back before."

"I think I'm enjoying it this time," she smiled, gasping a little as his hips rocked against hers once more. He reached into the pocket of his robe and pulled out her necklace, fastening it carefully around her neck.

The dialogue passed and hunger took over. He had been so long away from women, but he had not forgotten a thing. Confidently his pushed open her legs and began to trail kisses from her navel towards her core. He began to let his fingertips brush and explore, all the while keeping his eyes on hers—watching for a reaction.

He was certainly getting one. Katara's eyes were wide with arousal, her hands moving to her breasts as if it could ease the aching. Zuko placed his free hand over hers, taking over. With one hand he caressed her nipple gently, feeling it harden beneath his touch. With the other hand he began to slide his fingertips inside her. Her body convulsed ever so slightly with pleasure.

"Not yet," he murmured, focusing his tongue on her clit as his fingers began to enter her rhythmically.

"Zuko please," she moaned.

He had found her weak spot, just beneath her clit. He let the movements of his tongue become a little more forceful. He enjoyed the way she writhed under him, little gasps of pleasure escaping her lips every so often. He enjoyed being in control.

It was time. He could sense that she was not far now. His erection was so strong it was beginning to become uncomfortable. As he pulled away his pants Katara propped herself up on her elbows. She was looking at him hungrily. Sweat glistened against her muscular stomach and her cheeks were flushed.

She was incredibly wet. He could see it glisten in the light of the fire, which only turned him on more. As he began to push himself into her, there was no resistance. Her hips rocked towards him. Her mouth opened and her eyes closed as he went deeper.

Katara had thought the other boys from the water tribe were big, but they had nothing on Zuko. He filled her up completely. As he began to thrust she had the overwhelming desire to place her hands on his hips, to feel like she had some control. But she did not. Zuko was in complete control. When she felt close to coming he would slow, dragging her pleasure out to unbearable levels.

"Deeper," she moaned, burying the side of her face against the pillow and focusing all of her effort into hanging on a little longer.

As his rhythm became more merciless, Zuko began to feel Katara stiffen beneath him. _God, she is so tight._ Her body began to shake slightly, her lips parting in a silent groan. Zuko pushed deeper, and deeper, and harder.

She let out a groan of pleasure as he drove into her one last time. Breathing hard, Zuko let himself collapse against her body. It was hard to tell who was breathing harder.

Zuko pulled himself out of her and slipped his pants over his hips once more. A large part of him wanted to stay, to lean in the tenderness of long-term lover and kiss her full again and again, letting moments become minutes.

But no, he could not pretend that what had just transpired was a dream rather than reality. He had just slept with the enemy. Both their heads had begun to clear. Katara's loyalty returned, as did Zuko's pride. They separated, unable to look each other in the eye.

"I'll come for you in the morning," he said stiffly, snatching Katara's necklace from her neck. Having found the other half of his robe he exited the cabin—leaving Katara alone with her guilt.

The next day "Team Avatar" escaped. Zuko was left with nothing save for the pretty necklace that belonged to the pretty girl, and an insatiable hunger that food could never satisfy.


End file.
